Process for producing a structural concrete block

ABSTRACT

A process for producing a structural concrete block in which a preformed concrete block blank having alternate grooves and projections on one major surface thereof is fed to a predetermined position by intermittently driven conveying means, the conveying means is stopped to allow the blank to remain in the predetermined position and simultaneously, the blank is transferred to a guide member by a transfer mechanism, the conveying means is driven to feed a second similar concrete block blank, the conveying means is stopped and simultaneously, the transfer mechanisms transfers the second blank to the guide member so as to transfer the first blank to a cutting station in which a cutting blade having teeth on one surface for engaging the grooves in the blank is disposed and the blade is moved relative to the first blank to cut off the projections on the blank.

United States Patent [191 1 3,821,347 Katoh Y 1 June 28, 1974 1 PROCESS FOR PRODUCING A STRUCTURAL CONCRETE BLOCK [76] Inventor: Reichi Katoh, No. 12-5 Gakuenhigashi-cho, Kadaira-City, Tokyo, Japan [22] Filed: Feb. 15, 1973 [21] Appl. No.: 332,753

[30] Foreign Application Priority Data Oct. 19, 1972 Japan 47-103944 Oct. 23, 1972 Japan 47-105332 [52] U.S. Cl 264/162, 83/1, 83/4, 264/40, 425/289 [51] Int. Cl B28b 11/12, B28b ll/l8 [58] Field of Search 264/162, 40; 425/289, 295, 425/296, 298, 299, 315, 316, 302; 83/1, 4

g [56] References Cited UNITED STATES PATENTS 1,218,473 3/1919 Root 425/295 3,350,757 11/1967 Bowles 3,378,617 4/1968 Elmendorf 264/162 Primary Examiner-Robert F. White Assistant Examiner -Thomas P. Pavelko Attorney, Agent, or Firm-Wendcroth, Lind & Ponack [57] ABSTRACT A process for producing a structural concrete block in which a preformed concrete block blank having alternate grooves and projections on one major surface thereof is fed to a predetermined position by intermittently driven conveying means, the conveying means is stopped to allow the blank to remain in the predetermined position and simultaneously, the blank is transferred to a guide member by a transfer mechanism, the conveying means is driven to feed a second similar concrete block blank, the conveying means is stopped and simultaneously, the transfer mechanisms transfers the second blank to the guide member so as to transfer the first blank to a cutting station in which a cutting blade having teeth on one surface for engaging the grooves in the blank is disposed and the blade is moved relative to the first blank to cut off the projections on the blank.

2 Claims, 9 Drawing Figures PATENIEB II 1974 3.821. 347

sum 2 OF 5 PAIENTEDJme can I 3:821:34!

saw u or 5 PROCESS FOR PRODUCING A STRUCTURAL i CONCRETE BLOCK BACKGROUND OF THE INVENTION This invention relates to a process for producing a structural concrete block and a blade member employed in carrying out the process and more particularly, to a process for producing a concrete block having one surface simulant of a cut surface of portion of a natural rock formation from a preformed concrete block having alternate grooves and projections on one surface and a blade member having teeth on one surface for engaging in the grooves in the blank and cutting off the projections on the blank.

There have been proposed and known a great variety of structural concrete blocks having surfaces simultant of cut surfaces of a natural rock formation. However, such prior art structural concrete blocks have been conventionally produced by striking the upper surface of a preformed concrete block blank which is immovably held and has a size several times that of a desired or final concrete block by a blade or cutter with a great impact force to cut through the blank to the lower surface. The thus produced structural concrete block product may present a cut surface throughout which an irregular cut pattern is distributed, but such cut pattern is rather monotonous. In order to eliminate the disadvantage inherent in the above-mentioned prior art process for producing a structural concrete block, there has been proposed a process by which a portion of one surface of a concrete block blank is covered with a pattern plate and the remaining exposed portion of the surface is sand-blasted to be roughened.

However, such sand-blasting process cannot produce such a dynamic rough surface as one which is cut or broken by a blade with a great impact force because the sand-blasting process roughens the surface due to employing sand or grit particles and accordingly, the roughened surface produced by the sandblasting process is relatively fine and in addition, such process requires an additional step of covering the portion of the surface to be roughened with a pattern plate.

SUMMARY OF THE INVENTION Therefore, one principal object of the present invention is to provide a process for producing a structural concrete block which has on one surface in combination an irregular cut pattern portion simulant of a cut surface of a portion of a natural rock formation and a regular pattern portion.

Another object of the present invention is to provide a cutting blade member suitably employed in carrying out the process and adapted to produce a structural concrete block which has on one surface in combination an irregular cut pattern simulant of a cut surface of portion of a natural rock formation and a said blank pattern portion.

According to one aspect of the present invention,

there has been provided a process for producing a sturctural concrete block having on one surface in combination an irregular cut pattern portion simulant of a cut surface of a portion of a natural rock formation and a regular pattern portion, which comprises the steps of feeding said blank to a predetermined position by an intermittently driven conveyor, said blank having on one surface alternate grooves and projections, stopping the movement of said conveyor when the blank is positioned in said predetermined position, extending a transfer mechanism so as to transfer the blank onto a guide member, upon the transfer of said blank onto said guide member, retracting said transfer mechanism, driving said conveyor so as to feed a second similar blank to said predetermined position, stopping the movement of the conveyor when the second blank is positioned in the predetermined position, extending said transfer mechanism so as to transfer said second blank onto said guide member thereby to push said first-mentioned blank onto a cutting blade member in a cutting station, said cutting blade member having on one surface a plurality of teeth of the same pitch as the grooves on saidblank for engaging the grooves, actuating a blank holding down mechanism so as to hold said first-mentioned blank on said blade member against movement relative to the latter and moving said blade member relative to the blank so as to shear the projections on the blank.

The above and other objects and attendant advantages of the present invention will be more readily apparent to those skilled in the art. from a reading of the following detailed description in conjunction with the accompanying drawings which show one preferred embodiment of the invention for illustration purpose only, but not for limiting the scope of the same in any way.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary schematic top plan view of an apparatus suitably employed in carrying out the concrete block cutting process according to the present invention;

FIG. 2 is a fragmentary schematic side elevational view of said apparatus;

FIG. 3 is a cross-sectional view taken along substantially the line III-III of FIG. 1 and as seen in the direction of the arrows therein;

FIG. 4 is an isometric perspective view of a prefomied concrete block blank before the blank is processed by the process of the invention;

FIG. 5 is an isometric perspective view of a concrete block cutting means employed in said apparatus;

FIG. 6 is a sectional view showing the engaging relationship between the grooves in said preformed concrete block blank and the teeth on said cutting means in the cutting step of said process;

FIG. 7 is an isometric perspective view of a structural preformed concrete block obtained after the blank of FIG. 4 has been processed by the process of the invention especially showing the cut surface of the block which is simulant of a cut surface of a portion of a natural rock formation;

FIG. 8 is an isometric perspective view of a diferent type of preformed concrete block blank before the blank is processed by the process of the invention; and

FIG 9 is an isometric perspective view of a structural concrete block produced after the blank of FIG. 8 has been processed by the process of the invention especially showing the cut surface of the block which is simulant of a cut surface of a portion of a natural rock formation.

PREFERRED EMBODIMENT OF THE INVENTION The present invention will be now described referring to the accompanying drawings and more particularly, to FIGS. 4 and 8 which show two different types of preformed concrete block blanks before they are processed by the process of the invention. Reference will be first had to FIG. 4 which shows a concrete block blank A which has been preformed by any conventional concrete casting method employing a selected conventional mold and allowed to solidify to a suitable curing state to be processed by the process of the invention and the concrete blank has a rectangular hexahedral construction, for example. One of the two opposite major surfaces of the blank (the upper major surface as seen in FIG. 4) which constitutes the outer surface when the blank is processed and employed as an element in a structure such as a block wall, for example, has a plurality of equally spaced grooves l which extend across the full width of the surface and have an inverted trapezoid cross section (as seen in FIG. 4) and also a plurality of equally spaced projections 2 which also extend across the full width of the surface and have a trapezoid cross section (the-trapezoid orientation of the projections is opposite of that of the grooves). As seen in FIG. 4, each of the adjacent projections 2 is separated from another by the bottom of the groove 1 interposed therebetween. The preformed concrete block blank in FIG. 8 is substantially similar to that shown in FIG. 4 except that the grooved major surface of the block A is provided in the center thereof with a rectangular recess 3 in which a family emblem or any other desired decorative means is provided.

The process of the invention will now be described referring to FIGS. 1 through 3 inclusive in which a portion of a preferred form of apparatus suitably employed for carrying out the process is schematically shown.

An endless feed conveyor 10 which is adapted to be intermittently driven from a suitable conventional drive means (not shown) in the direction of arrow F FIG. 1) supports on the surface a plurality of preformed concrete block blanks A A A (see FIG. 2) in end to end relation with the grooved surfaces down and feeds the blocks A one at a time into the apparatus on the inlet side thereof during its predetermined intermitent movement. When the leading blank A, reaches a predetermined position within the apparatus as the blanks are fed by the intermittently driven conveyor 10, the leading end of the leading blank A contacts a limit switch 11 suitably mounted on the machine frame in a suitable position thereof and momentarily actuates the limit switch and at the same time, the conveyor 3 movement is stopped. The actuated limit switch 11 in turn actuates a transfer mechanism 15 which is also suitably mounted on the machine frame adjacent the opposite side of the blank A in the above-mentioned predetermined or limit switch actuation position within the apparatus and the transfer mechanism then pushes the blank A sideways in a direction perpendicular to the feed direction toward a cutting station C which is located on the side of the above-mentioned predetermined position opposite from the transfer mechanism 15. For this purpose, the transfer mechanism 15 comprises a hydraulically actuated cylinder 16 adapted to actuated in response to the actuation of the limit switch 11 and deactuated in response to the deenergization of the limit switch, a piston-rod assembly 17 reciprocally received in the cylinder 16 for movement between extended and retracted positions relative to the cylinder in response to theactuation and deactuation of the cylinder and a pusher member 18 integrally connected to the outer end of the rod of .the piston-rod assembly 15 for movement together with the piston-rod assembly 17. When extended, the piston-rod assembly 17 and accordingly, the pusher member 18 connected thereto pushes the concrete block which is now positioned in the predetermined position toward the cutting station C. Provided between the transfer mechanism 15 and cutting section C is a guide member 20 which is suitably mounted on the machine frame between the transfer mechanism 15 and cutting station C and provided on the surface with a plurality of guide rails 21 adapted to engage selected ones of the grooves I but not all of the grooves in the concrete block blank and which has a surface area substantially the same as that of one major surface of one concrete block blank. The cutting section C comprises a blade member 23 a detailed description of which will be given hereinafter referring to FIGS. 5 and 6 of the drawings. Although not shown, provided in the system including the limit switch 11 and cylinder unit 16, 17 and 18 are a relay adapted to be actuated in response to the actuation of the limit switch and an electromagnetic valve adapted to be actuated in response to the actuation of the relay to allow hydraulic fluid from a hydraulic source (not shown) to flow into the cylinder 16 to which the source is connected. The stroke of the piston-rod assembly 17 is just sufficient to push the concrete block blank in the predetermined position onto the guide member 20 and after having positioned the blank on the guide member 20, the pistonrod assembly retracts into the cylinder 16 leaving the blank on the guide member 20 and the thus positioned blank remains on the guide member until the pistonrod assembly 17 extends to push the blank A just following the leading blank A and thus, it will be apparent that the blank A, on the guide member 20 is indirectly pushed onto the blade 23 in the cutting station C by the piston-rod assembly 17 through the-following blank A as the piston-rod assembly moves the latter blank onto the guide member 20. The pusher member 18 has a switch actuation arm 19 extending upwardly at one end (the left-hand end as seen in FIG. 1) which is adapted to contact and momentarily actuate a limit switch 22 mounted on the machine frame in a position above the guide member 20 as the piston-rod assembly 17 extends to move the following blank and upon the actuation of the limit switch 10, the piston-rod assembly l7 commences to retract to the original position and at the same time, a hydraulically actuated holdingdown mechanism 25 is actuated to descend to firmly hold the blank A against the blade member 23 in the cutting station C in order to prevent the blank from moving relative to the blade member during the cutting operation which will be'described hereinafter.

The holding down mechanism 25 comprises a hydraulically actuated cylinder 26 adapted to be actuated in response to the actuation of the limit switch 22, a piston-rod assembly 27 reciprocally received in the cylinder 26 for extending from and retracting into the cylinder and a holding down member 28 integrally connected to the lower end of the piston-rod assembly for movement therewith toward and away from the blank on the blade member 23. Provided in the system including the limit switch 22 and holding down mechanism 25 are relay (not shown) adapted to be actuated ciated with the transfer and holding down mechanisms and 25, respectively, are connected.

When the piston-rod assembly 27 reaches the lower dead point of its stroke and accordingly, the holding down member 28 contacts against the blank on the blade member 23, the holding down member contacts and actuates a limit switch 30 mounted on themachine frame above the blade member 23 in the'cutting station C whereupon the limit switch actuates the drive means for the conveyor 10 (not shown) which is operatively connected to the limit switch and conveyor to drive the conveyor 10 to produce intermediate feed movement and at the same time, the cutting operation is commenced. v

The cutting blade member 23 formed of iron or steel is best shown in FIG. 5 of the drawings and has a rectangular hexahedral construction, for example. One of the major surfaces of the blade member 23 (the upper surface as seen in FIG. 5) is provided with a plurality of equally spaced teeth 23a the pitch of which corresponds to that of the grooves l in the concrete block blank A so that the teeth 23a may engage in the respectively associated grooves 1 when the blank A is transferred thereon from the guide member 20. As shown in FIG. 6, the teeth 23a extend across the full width of the blade member 23. The toothed surface of the blade member has a surface area substantially the same as or slightly larger than that of the opposite grooved surface of the blank. The height of the teeth 23a is greater than the depth of the grooves 1 so that a clearance 31 is defined by one flank of each tooth 23a and the bottom and one flank of the associated groove 1. With the engaging relationship between the teeth 23a and grooves l as described above, it has been experimentally confirmed that when the cutting blade member 23 is moved relative to the blank, each of the projections 2 on the blank is sheared off along substantially the one dot-chain line 32 as seen in FIG. 6. As shown in FIG. 6, although the cutting blade member 23 is moved horizontally relative to the concrete block, the shearing line 32 slopes upwardly from the left-hand flank to the right-hand flank of each of the projections 2 on the blank (as seen in FIG. 6) because the blade member 23 actually breaks the projections 2 and the breaking action by the blade member is transmitted from the lefthand flank of each projection 2 at a point spaced from the bottom of the associated groove 1 to the right-hand flank of the same projection at the bottom of another groove 1 adjacent the right-hand flank of the projection. The cutting blade 23 is further provided in the center of the opposite major surface or the surface opposite from the toothed surface with a trapezoidal recess 23b extending along the axis of the blade member. The above-mentioned cutting blade member 23 is movably supported on a guide block 33 with the teeth 23a engaging in the grooves l in the blank A, which guide block is fixedly mounted on the machine frame in the cutting station C and has on the upper surface a trapezoidal projection or guide portion 33a along which the recess 23b in the balde member 23 slides. The blade is connected at one end or theleft-hand end as seen in FIGS. 2 and 3 to the piston-rod 35 of a hydraulically actuated source (not shown) through an electromagnetic valve (not shown) which is in turn connected to a relay electrically connected to the limit switch 30. The cutting operation is commenced upon the momentary actuation of the limit switch 30 and the actuation of the limit switch actuates the cylinder 34 which in turn extends its piston-rod assembly 35 so as to move the cutting blade member 23 in the direction of arrow S as seen in FIG. 3 relative to thcfirmly held concrete blank A to shear or cut the projections 2 on the blank A. In order to reinforce the holding force on the blank against movement, a stop 36 is mounted on a bracket 37 which is in turn mounted on the machine frame and the position of the stop is so selected that when the blank A is transferred into the cutting station C, the right-hand end face of the blank A contacts or substantially contacts the stop 36. Thus, when the blade member 23 is moved horizontally relative to the blank A, the blank may initially follow the movement of the blade member only a slight distance against the holding down force on the blank from the holding down mechanism 25, but such movement of the blank is soon arrested by the stop 36. The cutting blade member 23 moves in the direction of arrow S upon the extension of the piston-rodassembly 35 as described hereinabove until the blade contacts and momentarily actuates a limit switch 38 mounted on a bracket 39 which is in turn mounted on the machine frame whereupon the piston-rod assembly 37 and accordingly, the holding down member 38 connected thereto is retracted from the blank thereby to release the blank from the holding down force and at the same time, the piston-rod assembly 35 is retracted thereby to return the cutting blade member 23 connected thereto to the originalposition. Meantime the conveyor 10 is advanced to feed the concrete block blank A3 to the above-described predetermined position in which the blank is opposite to the transfer mechanism 15 and the conveyor stops its feed movement. Upon having been positioned in the predetermined position, the leading end of the blank A contacts and momentarily actuates the limit switch 11 which in turn actuates the transfer mechanism 15 to extend the cylinder 16 and accordingly, the piston-rod assembly 17 and pusher member 18 pushes the blank A directly onto the guide member 20 and indirectly pushes the blank A which has been previously positioned on the guide member 20 onto the cutting blade member 23 in the cutting station C. Simultaneously, the processed concrete product A which is now on the cutting blade member 23 is pushed off the blade member by the incoming concrete blank A onto an endless discharge conveyor 40 which is positioned adjacent the discharge side of the apparatus and continuously driven by a conventional suitable drive means (not shown). Having pushed the blank A onto the guide member 22, the transfer mechanism 15 is retracted by contacting and actuating the limit switch 22 for the next cycle of transfer operation and the above described cutting operation is effected on the blank A which is now on the cutting blade member 23 in the manner as described above. By repeating the above-described operation cycle, products as shownin FIGS. 7 and 9 can be produced in succession. A

After having been processed in the manner described above, the concrete block blank A as shown in FIG. 4

will be converted to the product A as shown in FIG. 7, that is, the product A presents an irregular rough surface portion on the processed surface which is simulant of a cut surface of portion of a natural rock formation as shown in FIG. 7.

Similarly, after having been processed in the same way, the concrete block blank A as shown in FlG. 8 will have the processed surface as shown in FIG. 9 which is substantially similar to that of the product shown in FIG. 7 except for the recess 3.

In the above embodiment, the process of the invention has been described in connection with a product A (FIG. 7 or 9) having alternate grooved areas 1' and cut areas 2 throughout one major surface thereof. However, the process of the invention can produce products having a great variety of surface patterns by merely employing blade members having different tooth patterns. For example, when the center portions of the teeth 23a on the cutting blade member 23 are removed along the longitudinal axis of the blade member and such a blade member is employed for shearing the projections 2 on the concrete block blank A, the obtained product A will have the center portions of the projections uncut. Alternately, when the concrete block is preformed with a smooth surface area along the longitudinal axis thereof and alternate transverse grooves and projections which are broken by the smooth surface area on one major surface of the block and the cutting blade member is also provided with a nontoothed area along the longitudinal axis thereof and transverse'teeth which are broken by the nontoothed area, the obtained product will have the smooth area uncut.

In the above embodiment, it has been described that the preformed concrete block blank A is positioned on the cutting blade member 23, but according to the present invention, it may also be possible that the blade member is positioned on the blank. Furthermore, it is also possible that both the blade member and concrete block blank are disposed upright provided that the teeth on the blade member and the grooves in the concrete block blank engage each other and the projections on the blank can be cut or sheared by relative movement between the blade member and blank.

Although the best mode contemplated for carrying out the present invention has been herein shown and described, it will be apparent to those skilled in the art that various modifications and variations may be made without departing from what is regarded to be the subject matter of the invention.

What is claimed is:

1. A process for producing a structural concrete block having on one surface in combination an irregular cut pattern portion simulant of a cut surface of portion of a natural rock formation which comprises the steps of feeding said blank to a predetermined position by an intermittently driven conveyor, said blank having on one surface alternate grooves and projections, stopping the movement of said conveyor when the blank is positioned in said predetermined position, extending a transfer mechanism so as to transfer the blank onto a guide member, upon the transfer of said blank onto said guide member, retracting said transfer mechanism, driving said conveyor so as to feed a second similar blank to said predetermined position, stopping the movement of the conveyor when the second blank is positioned in the predetermined position, extending said transfer mechanism so as to transfer said second blank onto said guide member thereby to push said first-mentioned blank onto a cutting blade member in a cutting station, said cutting blade member having on one surface a plurality of teeth of the same pitch as the grooves on said blank for engaging the grooves, engaging the teeth of the cutting member with the grooves of the blank, actuating a blank holding down mechanism so as to hold said first-mentioned blank on said blade member against movement relative to the latter and moving said blade member relative to the blank so as to shear said projections on the blank.

2. The process as set forth in claim 1, in which said blank is fed by said conveyor with said grooves and projections down and said cutting blade member is positioned in said cutting station with said teeth up for engaging the grooves.

l l= l I 

1. A process for producing a structural concrete block having on one surface in combination an irregular cut pattern portion simulant of a cut surface of portion of a natural rock formation which comprises the steps of feeding said blank to a predetermined position by an intermittently driven conveyor, said blank having on one surface alternate grooves and projections, stopping the movement of said conveyor when the blank is positioned in said predetermined position, extending a transfer mechanism so as to transfer the blank onto a guide member, upon the transfer of said blank onto said guide member, retracting said transfer mechanism, driving said conveyor so as to feed a second similar blank to said predetermined position, stopping the movement of the conveyor when the second blank is positioned in the predetermined position, extending said transfer mechanism so as to transfer said second blank onto said guide member thereby to push said first-mentioned blank onto a cutting blade member in a cutting station, said cutting blade member having on one surface a plurality of teeth of the same pitch as the grooves on said blank for engaging the grooves, engaging the teeth of the cutting member with the grooves of the blank, actuating a blank holding down mechanism so as to hold said first-mentioned blank on said blade member against movement relative to the latter and moving said blade member relative to the blank so as to shear said projections on the blank.
 2. The process as set forth in claim 1, in which said blank is fed by said conveyor with said grooves and projections down and said cutting blade member is positioned in said cutting station with said teeth up for engaging the grooves. 